As a prior art relevant to the present invention, “emotion generating device and emotion generating method” disclosed in a patent document 1 is known. The emotion, which represents internal state of a human, variously changes depending on the situation. The patent document 1 discloses a technique for achieving generation of emotions under unforeseeable situation. That is, while referring to a foreseeable situation, the situation is estimated and emotion of the device itself is generated. Also, emotions actually generated in the past and the situations at that time are subjected to an analysis to learn unforeseeable collateral conditions peculiar to the respective situations and corresponding emotions. When a newly input situation fulfills the learnt collateral conditions, the emotion corresponding to the collateral conditions is outputted.
Also, the inventor of the present invention has disclosed “feeling generating method, feeling generating device and software” in a patent document 2. In this prior art, based on input information such as emotional state of the other party of a dialogue, instinct parameters representing comfort, a dangerous level and an achievement level are generated as motivating information, and based on the instinct motivating information, basic emotion such as delight, anger and the like are controlled to be generated. Particularly, the prior art was successful in generating more human-like emotional state by reflecting individuality such as rational nature and will to the control rules (in human, characteristics) when controlling to generate a basic emotion.
[Patent document 1] Japanese Unexamined Patent Application Publication No. Hei 11-265239
[Patent document 2] Japanese Unexamined Patent Application Publication No. 2002-215183